add developer environment for vscode

Problem: as a new developer it is hard to setup a local environment
Solution: provide a .devcontainer setup, including ruby, chef resources, Python, and tox, and a brief note about using the environment in the CONTRIBUTING.md
Signed-off-by: vsoch <vsoch@users.noreply.github.com>

.devcontainer/Dockerfile

@@ -0,0 +1,41 @@
+FROM ruby:2.7
+
+LABEL maintainer="Vanessasaurus <@vsoch>"
+
+# Match the default user id for a single system so we aren't root
+ARG USERNAME=vscode
+ARG USER_UID=1000
+ARG USER_GID=1000
+ENV USERNAME=${USERNAME}
+ENV USER_UID=${USER_UID}
+ENV USER_GID=${USER_GID}
+
+# Assuming extra libs could be installed to /usr/local
+ENV LD_LIBRARY_PATH=/usr/local/lib
+
+RUN apt-get update \
+ && apt-get -qq install -y --no-install-recommends \
+    sudo \
+    python3-pip \
+    python3 && \
+    pip3 install tox && \
+    ln -s /usr/bin/python3 /usr/bin/python && \
+    apt-get clean
+
+ENV CHEF_LICENSE=accept-no-persist
+COPY ./Gemfile /tmp/Gemfile
+COPY ./Gemfile.lock /tmp/Gemfile.lock
+RUN cd /tmp && \
+    bundle config set with 'style' && \
+    bundle install && \
+    curl -L https://omnitruck.cinc.sh/install.sh -o chefDownload.sh && \
+    chmod +x chefDownload.sh && \    
+    ./chefDownload.sh -c stable -P cinc-workstation
+
+# Add the group and user that match our ids
+RUN groupadd -g ${USER_GID} ${USERNAME} && \
+    adduser --disabled-password --uid ${USER_UID} --gid ${USER_GID} --gecos "" ${USERNAME} && \
+    echo "${USERNAME} ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers
+USER $USERNAME
+ENV PATH=/opt/chef-workstation/embedded/bin:$PATH
+ENV CHEF_LICENSE=accept-no-persist

.devcontainer/devcontainer.json

@@ -0,0 +1,33 @@
+{
+    "name": "AWS Cookbook Developer Environment",
+    "dockerFile": "Dockerfile",
+    "context": "../",
+
+    "customizations": {
+      "vscode": {
+        "settings": {
+          "terminal.integrated.defaultProfile.linux": "bash",
+
+          // Ensure that Python autocomplete works out of the box
+          "python.autoComplete.extraPaths": [
+            "/usr/local/lib/python3.8/site-packages",
+          ],
+          "python.analysis.extraPaths": [
+            "/usr/local/lib/python3.8/site-packages",
+          ]
+        },
+        // Note to Flux Developers! We can add extensions here that you like
+        "extensions": [
+          "ms-python.python", // Python support
+          "GitHub.vscode-pull-request-github", // manage and review PRs
+        ]
+      }
+    },
+  "features": {
+    "ghcr.io/devcontainers/features/github-cli:1": {
+      "version": "latest"
+    }
+  },
+  // Needed for git security feature (this assumes you locally cloned to flux-core)
+  "postStartCommand": "git config --global --add safe.directory /workspaces/aws-parallelcluster-cookbook"
+}

CONTRIBUTING.md

@@ -44,6 +44,41 @@ GitHub provides additional document on [forking a repository](https://help.githu
 Looking at the existing issues is a great way to find something to contribute on. As our projects, by default, use the default GitHub issue labels ((enhancement/bug/duplicate/help wanted/invalid/question/wontfix), looking at any ['help wanted'](https://github.com/aws/aws-parallelcluster-cookbook/labels/help%20wanted) issues is a great place to start. 
 
 
+## VSCode Developer Environment
+
+We provide a [.devcontainer](../.devcontainer) environment that you can open in VSCode, either automatically via the popup that will
+appear in the bottom right, or the command palette for DevContainer -> Reopen in container. The image comes with ruby 2.7 and dependencies installed and then you will shell in as the VSCode user (uid 1000) and can test style, run Python tests:
+
+```bash
+cookstyle .
+```
+
+or run Python tests (we have version 3.9 in the container)
+
+```bash
+tox -e py39-nocov
+```
+
+Or go to any of the cookbooks directories and run ChefSpec
+
+```bash
+cd cookbooks/aws-parallelcluster-awsbatch
+chef exec rspec
+cd cookbooks/aws-parallelcluster-computefleet
+chef exec rspec
+cd cookbooks/aws-parallelcluster-environment
+chef exec rspec
+cd cookbooks/aws-parallelcluster-platform
+chef exec rspec
+cd cookbooks/aws-parallelcluster-shared
+chef exec rspec
+cd cookbooks/aws-parallelcluster-slurm
+chef exec rspec
+```
+
+Although the uid of 1000 (for the vscode user) likely matches your system user, we recommend that you commit and otherwise interact with git from the outside,
+as likely your system credentials are in your actual user home.
+
 ## Code of Conduct
 This project has adopted the [Amazon Open Source Code of Conduct](https://aws.github.io/code-of-conduct). 
 For more information see the [Code of Conduct FAQ](https://aws.github.io/code-of-conduct-faq) or contact